What Is Legacy Code? Legacy code is source code inherited from someone else or inherited from an older version of the software. It can also be any code that you don't understand and that's difficult to change.

What is legacy code in testing?

In his book Working Effectively With Legacy Code, Michael Feathers gives a clear definition of what Legacy Code means to him: To me, legacy code is simply code without tests. This is an insight from years of experience. ... Generally, code without tests is tricky to change without introducing a regression somewhere.

What is a legacy code base?

Legacy code is older computer source code. It could simply refer to an organization's existing code base which has been written over many years, or it could imply a codebase that is in some respect obsolete or supporting something obsolete.